var delay = 4000; 
var noOfImgs = 5; 

pic0 = new Image(317,423); 
pic0.src = "box1.jpg"; 
pic1 = new Image(317,423); 
pic1.src = "box2.jpg"; 
pic2 = new Image(317,423); 
pic2.src = "box3.jpg";  
pic3 = new Image(317,423); 
pic3.src = "box4.jpg";  
pic4 = new Image(317,423); 
pic4.src = "box5.jpg";  

var imgArry = new Array() 
   imgArry[0] = "box1.jpg"; 
   imgArry[1] = "box2.jpg"; 
   imgArry[2] = "box3.jpg"; 
   imgArry[3] = "box4.jpg"; 
   imgArry[4] = "box5.jpg"; 

function rotateImage(imgNo) 
{ 
   clearTimeout(timerId);
   
    if(document.getElementById('leftImage1').src == imgArry[imgNo])
    {
        imgNo++;
    }
         
   if(imgNo == noOfImgs) 
   { 
      imgNo = 0; 
   } 
   else 
   { 
      document.getElementById('leftImage1').src = imgArry[imgNo]; 
      imgNo++; 
   } 
   var recur_call = "rotateImage('" + imgNo + "')"; 
   setTimeout(recur_call, delay); 
} 

var timerId = setTimeout('rotateImage(0)', 1500);